<!DOCTYPE html>
<html>
	<head>
		<meta charset="utf-8">
		<title>基本语法示例</title>
		<script>
			var name = "xiaoming";
			var a = 10;
			var b = NaN;
			var c;
			var d = null;
			document.write(typeof name);//数据类型检测typeof
			document.write("<br />");
			document.write(typeof a);//数据类型检测typeof
		document.write("<br />");
			document.write(typeof c);//数据类型检测typeof
			document.write("<br />");
		document.write(typeof d);//数据类型检测typeof
		document.write("<br />");
			document.write(a==b);
			document.write("<br />");
				document.write("===================================");
			document.write("<br />");
			var num1=12,num2='34',sum=0;
		sum=num1+num2;
			document.write(sum);
			document.write(typeof sum);
		</script>
	</head>
	<body>
	</body>
</html>
